Table 1 Search strategy of peer-reviewed articles

Participants

(teenage” OR “teenagers” OR “teen” OR “teens” OR “youth” OR “young” “youngster” OR” youngsters” OR “young adult” OR “juvenile” OR “adolescent” OR “adolescents” OR “adolescence)

Interventions

"psychological relaxation" OR "mental relaxation" OR "physiological relaxation" OR "therapeutic relaxation" OR "relaxation training" OR "relaxation technique*" OR breathing OR "slow breathing" OR "deep breathing" OR meditation OR "progressive muscle relaxation" OR "imagery" OR "Autogenic training" OR spirituality OR walking OR gardening OR yoga OR "T'ai chi" OR Qigong OR massage OR acupuncture OR "Feldenkrais Method" OR myotherapy OR reflexology OR self-regulation OR autosuggestion OR prayer OR hypnosis OR Pranayama OR biofeedback OR music OR art-therapy OR stress-management OR writing OR exercise OR aromatherapy OR hydrotherapy OR laughing-therapy OR food-therapy OR mindfulness)

Conditions

(“Depression" OR “depressive disorder” OR “depressive symptoms” OR “depressed” OR “anxiety” OR “anxieties” OR “anxiety symptoms” OR “anxiety disorder” OR “anxiety disorders”)

Outcomes

Mental health” OR psychosocial OR “Well-being” OR “self-esteem” OR social OR suicide OR suicidality OR distress OR depress* OR stress OR anxiety OR anxious OR emotional OR internaliz* OR externaliz*

Study design

(“Clinical trial” OR intervention OR trial OR “randomized controlled trial” OR RCT OR “cluster randomized control trial”)

Region

N/A